The adapter and the power supply are electronic apparatuses used frequently in our daily life. Taking the adapter as an example, it is generally employed for rectifying and converting the external AC power into the DC power, so as to supply the required power to an electric appliance, such as a notebook, or charge the charging battery.
Please refer to FIG. 1, which shows the casing of the conventional adapter. The casing of the conventional adapter 1 includes an upper casing 11 and a lower casing 12, in which the upper casing 11 and the lower casing 12 can be engaged with each other, and a space is provided between the upper casing 11 and the lower casing 12 for receiving a printed circuit board 13. When the upper casing 11 and the lower casing 12 are engaged with each other, a first opening and a second opening are formed on the opposite surfaces of the assembled casing for fixing a socket 14 and a power cord 15 therein, respectively. The socket 14 and the power cord 15 can be electrically connected with the printed circuit board 13, respectively. Thereby, the external power can be provided to the printed circuit board 13 through the socket 14, and the power converted by the printed circuit board 13 can be provided to the electric appliance for usage through the power cord 15.
With the integration of the integrated circuit, the volume of the electronic apparatus is also decreased, which results in the difficulty of heat-dissipation. A large amount of heat is usually generated from the electronic elements on the printed circuit board during the operation of the adapter. However, the upper and lower casings of the conventional adapter are made of plastic, and it is obvious that the heat is hard to dissipate and would accumulate in the interior of the adapter since the plastic has low heat-conductance coefficient. If the heat accumulated within the adapter cannot be dissipated efficiently, the electronic elements in the adapter will be damaged easily, and thus, not only the lifespan but also the power converting efficiency of the adapter will be decreased significantly.
For overcoming the problem of heat-dissipation, an adapter 1 as shown in FIG. 2 is provided in the market, which has plural heat-dissipating holes 20 formed on the upper and lower casings 11, 12. However, via the design of the heat-dissipating holes 20, the heat generated in the adapter 1 can only be dissipated by convection due to the temperature difference between the interior and the exterior of the adapter 1, and the heat-dissipating performance thereof is not good enough. In addition, another type of adapter (not shown) is also provided in the market, which has a small heat-dissipating fan and wind exits for driving out the heat accumulated in the interior of the adapter. However, such design limits the miniaturization of the adapter, and the heat generated in the adapter cannot be evenly dissipated by the heat-dissipating fan, so that the temperature of the adapter cannot be equalized, and thus the heat accumulating in the dead space for heat-dissipation may cause damages to the neighboring electronic elements.
Furthermore, for the user of the portable notebook, since the adapter becomes hot after it is used for a period of time, the user may be scalded when touching the adapter. Therefore, to overcome the disadvantages of the prior art described above, it is needed to provide a heat-dissipating casing of an electronic apparatus which has effects of heat-dissipation, temperature-equalization and scald-prevention.